The effect of salinity on growth and lipid composition of a moderately halophilic Gram-negative bacterium HX

1990 ◽  
Vol 68 (1) ◽  
pp. 249-254 ◽  
Author(s):  
Rachel L. Adams ◽  
Margot Kogut ◽  
Nicholas J. Russell
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Lipid Composition ◽  
Culture Medium ◽  
Phospholipid Composition ◽  
Sudden Increase ◽  
Gram Negative ◽  
Moderately Halophilic ◽  
Nacl Concentration ◽  
Salinity Shift

The effect of NaCl concentration on the growth rate and phospholipid composition of a moderately halophilic Gram-negative rod-shaped bacterium has been studied. This bacterium, designated HX, grows between 0.5 and 4.25 M NaCl at 20, 30, and 37 °C. It has a broad optimum salt concentration for growth of 1.0–2.0 M NaCl at 20 and 30 °C and 1.5–2.8 M NaCl at 37 °C. Its major lipids are phosphatidylethanolamine and phosphatidylglycerol, which constitutes >90% of the total lipid, together with smaller amounts of diphosphatidylglycerol; there are traces of an unidentified glycolipid, lysophosphatidylethanolamine, and phosphatidylserine. Lipid composition depends on NaCl concentration of the culture medium: at higher salinities the proportion of anionic phospholipids, mainly phosphatidylglycerol, is greater relative to the proportion of zwitterionic phospholipids, mainly phosphatidylethanolamine. The major fatty acids are 16:0, 16:1, 18:0, 18:1, 17:0cyc, and 19:0cyc; the proportions of the cyclopropane fatty acids are greater in cultures grown at higher salinities and this increase is due to NaCl concentration, not growth rate. Following a sudden increase in NaCl concentration of the culture medium (shift up), there are concomitant changes in growth rate and phospholipid composition. A lag period in growth is observed only when the magnitude of the salinity shift up is at least threefold. After a salinity shift up, there is a rapid decrease in the ratio of phosphatidylethanolamine to phosphatidylglycerol. It appears that the alterations in growth rate and lipid composition are a physiological response for adaptation to a change in salinity.Key words: halophilic bacteria, haloadaptation, membranes, lipids, salinity.

scholarly journals Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria

2011 ◽  
Vol 80 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Leona Buňková ◽  
František Buňka ◽  
Rahula Janiš ◽  
Jiří Krejčí ◽  
Iva Doležálková ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Specific Growth ◽  
Lag Time ◽  
Gram Negative Bacteria ◽  
Inhibitory Effects ◽  
Gram Negative ◽  
Food Borne Pathogens ◽  
Food Borne

The aim of this study was to compare under the same conditionsin vitrothe inhibitory effects of seven 1-monoglycerides (MAG) containing fatty acids with a medium chain on ten strains of food-borne pathogens or spoilage gram-positive and gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella entericaser.Enteritidis andPseudomonas aeruginosa) and on their growth indicatos. The inhibitory effect of MAGs (monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, MAG of undecanoic and 10-undecenoic acids) at a concentration of 25 – 1500 mg·l-1was observed. Growth of bacteria in the presence of MAG was studied by means of optical density of bacteria for 24 h. The data were modelled through a Gompertz equation and the lag-time, the maximum specific growth rate and the maximal value reached were calculated. MAGs inhibited mainly the growth of gram-positive bacteria, which was shown by the extended lag-time, decrease in specific growth rate and decrease in cell density. Inhibitory effects of tested MAGs could be ranked from point of view of the minimum inhibitory concentration: MAG-C12:0 > MAG-C11:0 > MAG-C10:0 > MAG-C14:0 > MAG-C11:1 > MAG-C8:0 > MAG-C16:0.In vitro, no significant inhibitory effects of 1-monoglycerides, with the exception of the highest concentrations applied, on the growth of gram-negative bacteria were detected. The main contribution of this study is to compare the effects of several MAG containing fatty acids with a medium chain under the same conditions on the growth indicators of bacteria.

Myocardial lipid metabolism in cardiac hyper- and hypo-function. Studies on triiodothyronine-treated and transplanted rat hearts

1977 ◽  
Vol 55 (6) ◽  
pp. 1311-1319 ◽  
Author(s):  
S. C. Vasdev ◽  
B. Korecky ◽  
R. B. Rastogi ◽  
R. L. Singhal ◽  
K. J. Kako
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Erucic Acid ◽  
Experimental Model ◽  
Lipid Composition ◽  
Mechanical Performance ◽  
Phospholipid Composition ◽  
Adult Rats ◽  
Rat Hearts

Lipid composition of the myocardium and in vitro lipid metabolism were studied in hearts from young rats after 30 days of treatment with triiodothyronine (100 μg/kg per day) and in heterotopically isotransplanted hearts of inbred adult rats 6 days after surgery. The former served as an experimental model of cardiac hyperfunction, while the latter, empty beating hearts, served as a model of cardiac hypofunction. In hearts from hyperthyroid animals the concentration of phosphatidylcholine, phosphatidylethanolamine, cardiolipin, and the incorporation of 14C-labelled palmitic and erucic acid into these phospholipids were increased significantly as compared with controls. In contrast, the triglyceride concentration and the incorporation of palmitate into triglyceride were significantly decreased. In transplanted hearts, the phospholipid concentration and the incorporation of 14C-labelled fatty acids into phospholipids were significantly decreased as compared with the hearts of the inbred host rats of the same age. The results indicate that the mechanical performance of the heart affects the phospholipid composition, which maybe a reflection of increased or decreased proliferation of subcellular membranes in sustained cardiac hyper- or hypo-function.

scholarly journals Exogenous polyunsaturated fatty acids (PUFAs) promote changes in growth, phospholipid composition, membrane permeability and virulence phenotypes in Escherichia coli

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Joshua L. Herndon ◽  
Rachel E. Peters ◽  
Rachel N. Hofer ◽  
Timothy B. Simmons ◽  
Steven J. Symes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Membrane Permeability ◽  
Phospholipid Composition ◽  
Acid Oxidation ◽  
Gram Negative Bacteria ◽  
Membrane Phospholipids ◽  
Gram Negative ◽  
E Coli

Abstract Background The utilization of exogenous fatty acids by Gram-negative bacteria has been linked to many cellular processes, including fatty acid oxidation for metabolic gain, assimilation into membrane phospholipids, and control of phenotypes associated with virulence. The expanded fatty acid handling capabilities have been demonstrated in several bacteria of medical importance; however, a survey of the polyunsaturated fatty acid responses in the model organism Escherichia coli has not been performed. The current study examined the impacts of exogenous fatty acids on E. coli. Results All PUFAs elicited higher overall growth, with several fatty acids supporting growth as sole carbon sources. Most PUFAs were incorporated into membrane phospholipids as determined by Ultra performance liquid chromatography-mass spectrometry, whereas membrane permeability was variably affected as measured by two separate dye uptake assays. Biofilm formation, swimming motility and antimicrobial peptide resistance were altered in the presence of PUFAs, with arachidonic and docosahexaenoic acids eliciting strong alteration to these phenotypes. Conclusions The findings herein add E. coli to the growing list of Gram-negative bacteria with broader capabilities for utilizing and responding to exogenous fatty acids. Understanding bacterial responses to PUFAs may lead to microbial behavioral control regimens for disease prevention.

Study on biocharacteristics and puruvate production of moderately halophilic bacteria isolated from dunalliella tertiolecta’s culture medium

2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Hoang Thi Lan Anh ◽  
Luu Thi Tam ◽  
Dang Diem Hong
Keyword(s):  
Fatty Acids ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Culture Medium ◽  
Sequence Similarity ◽  
Halophilic Bacteria ◽  
Rrna Gene ◽  
Wild Type ◽  
Moderately Halophilic ◽  
Moderately Halophilic Bacteria

A moderately halophilic bacteria designed strain D34 was isolated from the culture medium of green microalga Dunaliella tertiolecta. The isolate was Gram-negative, aerobic, rod-shaped, approximately 0.45–0.60 mm wide and 1.25–5.10 mm long, occuring singly, non-motile, and flagellum- less. Colonies on solid media are cream, circular, and smooth. This strain was able to produce exopolysaccharide, poly hydroxybutyrate, oxidase and catalase positive. Growth occurred in a temparature range of 20–40°C, a salts concentration of 0.1–25% (w/v), and pH range 6–12. The major fatty acids were C16:0 (35.59%), C16:1w-7 (20.54%), C18: 1w-7 (30.14%), and C12:0 (10.03% of total fatty acids). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain D34 belonged to the genus Halomonas. The highest levels of 16S rRNA gene sequence similarity were found between the strain D34 and H. aquamarina (sequence similarity 98.6 %).Pyruvate, a central intermediate in metabolism processes in all organisms, is widely used for the synthesis of various chemicals and polymers as well as ingredient or additive in food, cosmetics, and pharmaceuticals. In this study, pyruvate production by strain D34 following changes in culture medium, glucose and nitrate concentrations and culture temperature were also studied. In 84 hours of batch- cultivation, pyruvate production by wild-type Halomonas sp. D34 reached 37.24 g/L at 37°C with 20% glucose and 30 g/L sodium nitrate adding to SOT medium. These data provided evidences for pyruvate production using novel wild-type strains. 

scholarly journals LIPID COMPOSITION AND MEMBRANOPROTECTIVE ACTION OF EXTRACT FROM MARINE GREEN ALGAE ULVA LACTUCA (L.)

2019 ◽  
pp. 41-51
Author(s):  
Svetlana Yevgen'yevna Fomenko ◽  
Natal'ya Fedorovna Kushnerova ◽  
Vladimir Gennad'yevich Sprygin ◽  
Elena Sergeyevna Drugova ◽  
Larisa Nikolayevna Lesnikova ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Green Alga ◽  
Lipid Composition ◽  
Lipid Fraction ◽  
Phospholipid Composition ◽  
Ulva Lactuca ◽  
Erythrocyte Membranes ◽  
Total Lipids ◽  
Alcohol Extract ◽  
Reference Preparation

The object of the present study was a water-alcohol extract obtained from the dried thallus of the marine green alga Ulva lactuca (L.) (syn.: Ulva fenestrate P. et R.) – ulva lettuce. Glycolipids (40.6%) and neutral lipids (34%) prevailed in the lipid fraction of the extract; phospholipids contained 13.4% of the total lipids. The content of polyunsaturated fatty acids (PUFA) was 50% of the total amount of fatty acids, among which PUFA of the n-3 family predominated (37.43%). On the model of toxic hepatitis induced by the introduction of carbon tetrachloride (CCl4) (50% solution in olive oil, subcutaneously 2 ml/kg for 4 days), we study the effect of the lipid fraction of U. lactuca extract and the commercial reference preparation Essentiale® on the physiological and biochemical characteristics of erythrocytes and lipid composition of erythrocyte membranes in rats. The introduction of the lipid fraction from the ulva (dose 80 mg of total lipids per kg of body weight) to the animals intragastrically for 7 days after withdrawal of CCl4 exerted a protective effect, which was manifested in the restoration of the erythrocyte size characteristics (average volume and diameter), their osmotic resistance to hemolysis, levels of malondialdehyde and reduced glutathione, as well as maintaining of the ratio of phospholipid fractions. Under the damaging effects of CCl4, the lipid fraction from the green alga U. lactuca was not inferior to the effectiveness of reference preparation Essentiale® in restoring of the physiological characteristics of erythrocytes and the phospholipid composition of its membranes.

scholarly journals Enterococcus faecalis Readily Adapts Membrane Phospholipid Composition to Environmental and Genetic Perturbation

2021 ◽  
Vol 12 ◽  
Author(s):  
Brittni M. Woodall ◽  
John R. Harp ◽  
William T. Brewer ◽  
Eric D. Tague ◽  
Shawn R. Campagna ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Enterococcus Faecalis ◽  
Lipid Composition ◽  
Lipid Membrane ◽  
High Resolution Mass Spectrometry ◽  
Phospholipid Composition ◽  
Specific Gene ◽  
Polar Head ◽  
Head Groups

The bacterial lipid membrane, consisting both of fatty acid (acyl) tails and polar head groups, responds to changing conditions through alteration of either the acyl tails and/or head groups. This plasticity is critical for cell survival as it allows maintenance of both the protective nature of the membrane as well as functioning membrane protein complexes. Bacteria that live in fatty-acid rich environments, such as those found in the human host, can exploit host fatty acids to synthesize their own membranes, in turn, altering their physiology. Enterococcus faecalis is such an organism: it is a commensal of the mammalian intestine where it is exposed to fatty-acid rich bile, as well as a major cause of hospital infections during which it is exposed to fatty acid containing-serum. Within, we employed an untargeted approach to detect the most common phospholipid species of E. faecalis OG1RF via ultra-high performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). We examined not only how the composition responds upon exposure to host fatty acids but also how deletion of genes predicted to synthesize major polar head groups impact lipid composition. Regardless of genetic background and differing basal lipid composition, all strains were able to alter their lipid composition upon exposure to individual host fatty acids. Specific gene deletion strains, however, had altered survival to membrane damaging agents. Combined, the enterococcal lipidome is highly resilient in response to both genetic and environmental perturbation, likely contributing to stress survival.

scholarly journals Exogenous polyunsaturated fatty acids (PUFAs) promote changes in growth, phospholipid composition, membrane permeability and virulence phenotypes in Escherichia coli

2020 ◽  
Author(s):  
Joshua Herndon ◽  
Rachel Peters ◽  
Rachel Hofer ◽  
Tim Simmons ◽  
Steven Symes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Membrane Permeability ◽  
Phospholipid Composition ◽  
Acid Oxidation ◽  
Gram Negative Bacteria ◽  
Membrane Phospholipids ◽  
Gram Negative ◽  
E Coli

Abstract Background: The utilization of exogenous fatty acids by Gram-negative bacteria has been linked to many cellular processes, including fatty acid oxidation for metabolic gain, assimilation into membrane phospholipids, and control of phenotypes associated with virulence. The expanded fatty acid handling capabilities have been demonstrated in several bacteria of medical importance; however, a survey of the polyunsaturated fatty acid responses in the model organism Escherichia coli has not been performed. The current study examined the impacts of exogenous fatty acids on E. coli. Results: All PUFAs elicited higher overall growth, with several fatty acids supporting growth as sole carbon sources. Most PUFAs were incorporated into membrane phospholipids as determined by ultra performance liquid chromatography-mass spectrometry, whereas membrane permeability was variably affected as measured by two separate dye uptake assays. Biofilm formation, swimming motility and antimicrobial peptide resistance were altered in the presence of PUFAs, with arachidonic and docosahexaenoic acids eliciting strong alteration to these phenotypes. Conclusions: The findings herein add E. coli to the growing list of Gram-negative bacteria with broader capabilities for utilizing and responding to exogenous fatty acids. Understanding bacterial responses to PUFAs may lead to microbial behavioral control regimens for disease prevention.

scholarly journals Exogenous Polyunsaturated Fatty Acids (PUFAs) Promote Changes in Growth, Phospholipid Composition, Membrane Permeability and Virulence Phenotypes in Escherichia Coli

2020 ◽  
Author(s):  
Joshua Herndon ◽  
Rachel Peters ◽  
Rachel Hofer ◽  
Steven Symes ◽  
David Giles
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Membrane Permeability ◽  
Phospholipid Composition ◽  
Acid Oxidation ◽  
Gram Negative Bacteria ◽  
Membrane Phospholipids ◽  
Gram Negative ◽  
E Coli

Abstract Background: The utilization of exogenous fatty acids by Gram-negative bacteria has been linked to many cellular processes, including fatty acid oxidation for metabolic gain, assimilation into membrane phospholipids, and control of phenotypes associated with virulence. The expanded fatty acid handling capabilities have been demonstrated in several bacteria of medical importance; however, a survey of the polyunsaturated fatty acid responses in the model organism Escherichia coli has not been performed. The current study examined the impacts of exogenous fatty acids on E. coli.Results: All PUFAs elicited higher overall growth, with several fatty acids supporting growth as sole carbon sources. Most PUFAs were incorporated into membrane phospholipids as determined by thin-layer chromatography and UPLC-mass spectrometry, whereas membrane permeability was variably affected as measured by two separate dye uptake assays. Biofilm formation, swimming motility and antimicrobial peptide resistance were altered in the presence of PUFAs, with arachidonic and docosahexaenoic acids eliciting strong alteration to these phenotypes.Conclusions: The findings herein add E. coli to the growing list of Gram-negative bacteria with broader capabilities for utilizing and responding to exogenous fatty acids. Understanding bacterial responses to PUFAs may lead to microbial behavioral control regimens for disease prevention.

Interactive effects of salt concentration and temperature on growth and lipid composition in the moderately halophilic bacterium Vibrio costicola

1992 ◽  
Vol 38 (8) ◽  
pp. 823-827 ◽  
Author(s):  
Rachel L. Adams ◽  
Nicholas J. Russell
Keyword(s):  
Growth Temperature ◽  
Lipid Composition ◽  
Acyl Chain ◽  
Halophilic Bacteria ◽  
Interactive Effects ◽  
Lipid Phase ◽  
Lower Growth ◽  
Moderately Halophilic ◽  
Moderately Halophilic Bacterium ◽  
Nacl Concentration

The interactive effects of NaCl concentration and growth temperature on the growth and lipid composition of the moderately halophilic eubacterium Vibrio costicola have been investigated. Vibrio costicola was shown to be capable of growth over the temperature range 4–37 °C. Maximum growth yields were obtained at 30 °C when the optimum NaCl concentration was 1.0 M NaCl. In contrast with some previous studies, at higher or lower growth temperatures both the optimum and lower limit of NaCl concentration were higher, but there was no change in the upper limit of NaCl concentration for growth. There were no differences between the lipid compositions of cultures grown in 1 M NaCl at 30 or 37 °C, but as the growth temperature was lowered from 30 to 10 or 4 °C, the ratio of phosphatidylethanolamine to phosphatidylglycerol increased significantly as a result of the conversion of phosphatidylglycerol to diphosphatidylglycerol; in addition, at the lower growth temperatures the phospholipid fatty acyl composition became more unsaturated and the mean acyl chain length was shorter. It is suggested that the altered salt dependence of V. costicola at temperatures below the optimum for growth is due to a modification in membrane lipid phase behavior and stability brought about by changes in lipid composition, whereas a different mechanism operates above the growth temperature optimum. Key words: salinity, halophilic bacteria, temperature, Vibrio costicola, lipid composition, nonbilayer phases of lipids.

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